a. Field of the Invention
The present invention relates to a high magnification (50.times. to 70.times.) microscrope objective wherein longitudinal chromatic aberration is completely corrected to a degree similar to that in a semiapochromat objective especially over a large numerical aperture of 0.95 and curvature of field is also favourably corrected.
B. Description of the Prior Art
Conventional microscope objective having magnification of 60.times. or so were not satisfactory in their performance since they had numerical apertures of 0.7 to 0.8 and their chromatic aberration was corrected only to the degree similar to that in an ordinary apochromat. In such circumstances, it has been strongly desired to develop a microscrope objective having higher performance. Although there were available microscope objective having numerical apertures larger than 1.0 and wherein chromatic aberration was corrected, such objective were liquid immersions and required tedious operating procedures.